Method for dosing reinforcing fibres for the manufacturing of fibre concrete and the chain packing used

ABSTRACT

A method for dosing reinforcing fibers in a mixing silo during the manufacture of fiber concrete. The reinforcing fibers as supplied in a chain packing of sacks. The sacks may be made of material which can be disintegrated in mortar or concrete. The chain packing including sacks filled with reinforcing fibers for carrying out the method may be made of material which can be disintegrated in mortar or concrete.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. application NO.PCT/EP02/04566, filed Apr. 24, 2002, which U.S. application no.PCT/EP02/04566 claims the priority of Belgium application no. 2001/0309,filed May 4, 2001, and each of which is incorporated herein byreference.

[0002] This application relates to Applicant's concurrently filedco-pending application entitled “Closed Reinforcement Fiber Package, AsWell As Chain Packing Consisting Of Such Closed Packages” (Applicant'sref. no. 7330), which is a continuation of U.S. application no.PCT/EP02/02455, filed Mar. 5, 2002, and which U.S. application no.PCT/EP02/02455 claims the priority of Belgium application no. 2001/0309,filed May 4, 2001.

[0003] The invention relates to a method for dosing reinforcing fibresin a mixing silo during the manufacturing of fibre concrete.

[0004] For the manufacturing of fibre concrete or concrete reinforcedwith reinforcing fibres it is extremely important to supply the exactquantity of reinforcing fibres to the mixture of components of mortar orconcrete. It is possible to store the different components oringredients of the concrete to be manufactured in separate silos and tosupply the exact quantity of each of these components to the mixingsilo.

[0005] The supply of the exact quantity of reinforcing fibres, such assteel fibres, is extremely difficult. This is certainly the case whenthe mixture is made on the building yard itself.

[0006] Numerous solutions have already been proposed, such as inEP-A-522.029 (WO 91/14551); EP-A499.572; AP-A499.573; DE 29714704U;DE-A-3.412.216; DE-A4.427.156; FR-A-2.672.045 and many other patentdocuments.

[0007] A disadvantage of the known solutions is that they all need arather complex dosing machine or weighing machine.

[0008] Another disadvantage is that the weighing or dosing ofreinforcement fibres in a concrete mixing plant or on a building yard isa cumbersome and time-consuming operation.

[0009] The invention intends to avoid the aforementioned disadvantages.

[0010] Therefore, the invention proposes for a method mentioned in theopening lines that the reinforcing fibres are supplied in a chainpacking of sacks mad of a material that can be disintegrated in mortaror concrete.

[0011] It has to be noted that it is already known to pack thereinforcing fibres in sacks that can be disintegrated in mortar orconcrete. This has amongst others already been described inDE-A4.214-540 and WO 95/11861.

[0012] An important variant of the method according to the invention ischaracterised in that the reinforcing fibres are supplied in a chainpacking of sacks, that the sacks are cut open above the mixing silo as aresult of which the reinforcing fibres fall in the mixing silo and thatthe empty chain packing is conveyed away.

[0013] In the latter case, the sacks can be made of a material thatcannot be disintegrated in mortar or concrete. The removal of the emptychain packing can be assured by a known roll system.

[0014] In a preferred method according to the invention, the sacks arejoined to each other.

[0015] The great advantage of the method according to the invention isthat the reinforcing fibres are now supplied to the mixing silo in acontinuous chain packing of sacks. It is now possible to supply acorrect, well-defined quantity of reinforcing fibres in the sacks duringthe manufacturing of the reinforcing fibres. This makes it possible tosupply the exact quantity of reinforcing fibres to the mixing silo bymeans of a conveyor belt, a roll system or a similar alimentationdevice, in which the former dosing or weighing operations are replacedby a measuring operation of the length of the continuous chain packingor a counting operation of the number of supplied sacks to the mixingsilo.

[0016] By fibre concrete, we understand all curing materials, providedwith reinforcing fibres, such as steel fibres, glass fibres andsynthetic fibres, such as polypropylene fibres to improve the propertiesof the curable material.

[0017] The invention will be further explained in the followingdescription by means of the accompanying drawing.

[0018] In the drawing, FIGS. 1 and 2 give a representation, bothschematically and in perspective, of parts of the chain packingaccording to the invention.

[0019] In FIG. 1, the chain packing or chain package applied accordingto the method according to the invention is generally indicated by 1.The chain packing or package 1 consists of a large number of sacks 2that are joined together. The sacks 2 may be made of a material that canbe disintegrated in mortar or concrete.

[0020] As already mentioned above, it is already known to mixingredients in concrete, stored in sacks, such as e.g. cellulose, whichdisintegrate in water. Preferably, a cellulose-based foil is used forthe sacks 2; such foil will also be used as basic material for paper,possibly, such as known in the paper branch of industry, with additionof water-soluble glue and fillers, which are harmless to the concrete.The sacks can e.g. be glued together and closed with water-solubleheat-adhesive. But it is clear that every foil that disintegrates in theconcrete water within the usual mixing time can be used.

[0021] It is also possible to manufacture the sacks 2 of the chainpacking 1 in a material that cannot be disintegrated in mortar orconcrete. In that case, the sacks 2 are cut open above the mixing siloby means of a known cutting device as a result of which the reinforcingfibres 2 fall in the mixing silo. The continuous empty chain packing 1is then conveyed by means of a known roll system. The advantage of thismethod consists in the fact that no chain packing 1 material falls inthe mixing silo.

[0022] In FIG. 1, the reinforcing fibres, packed in the sacks 2, areindicated by 3. The reinforcing fibres 3 can be made of all sorts ofmaterials. This depends on the demands required of the fibres and on thefibre concrete to be reinforced. Preferably, steel reinforcing fibres 3are used, sold amongst others by the applicant N. V. Bekaert S. A. underthe brand name DRAMIX. Mostly, steel fibres 3 are used with a tensileforce comprised e.g. between 500 and 3000 N/mm².

[0023] The used fibres can e.g. be straight. This is the simplest andcheapest version of reinforcing fibres that can be used for reinforcing.Preferably, the reinforcing fibres have a form that makes it ratherdifficult to pull them out of the cured concrete material using atensile strain. To that end, the fibres are e.g. corrugated or theircross-section-surface varies along the length. For steel fibres, thethickness or diameter preferably varies from 0.15 to 1.2 mm. Thelength-diameter ratio for steel fibres is, for practical and economicalreasons, mostly situated between 10 and 200 and preferably minimallyamounts to 40. For non-straight fibres, the length is the rectilineardistance between the ends of the fibres, whereas the diameter of fibresof which the diameter varies along the length is defined as the averagediameter over the entire length.

[0024] As FIG. 1 shows, the reinforcing fibres 3 are preferably situatedin a mainly mutually parallel position in the sack 2. In the event ofsteel fibres, the weight of the total number of fibres per sack 2 variesbetween 100 grams and 2 kg. It is also possible to use without anyproblems sacks weighing more than 2 kg.

[0025] The packing and weighing of steel fibres, such as describedabove, can be executed in line with the actual production of the steelfibres or on another spot, separated from the actual manufacturing ofthe steel fibres. It is e.g. possible to place the steel fibres 3 in amainly mutual parallel position by means of magnetic forces.

[0026] Preferably, the length of the steel fibres 3 is practicallyidentical to the length of the sack 2 and the steel fibres 3 aresituated lengthwise the sack 2. The chain packing 1 preferably consistsof sacks 2 that are joined in line. It is also possible to mak sure thatthe length of the steel fibres 3 is practically identical to the widthof the sacks 2 and that the fibres 3 are situated widthwise the sack 2.

[0027]FIG. 2 shows a chain packing 1, whereby the sacks 2 with one sidethereof are connected to a tape or strip 4. The strip 4 can also be awire, a cord or the like. The strip 4 can be made of a material that canbe disintegrated in mortar or concrete to be reinforced.

[0028] It is obvious that the chain packing 1 according to the inventionmakes it now possible to easily supply such continuous packings 1 to themixing silo by means of simple means of transportation, such as aconveyor belt, allowing in a simple way by means of a counter to countthe number of sacks 2 or by means of a simple measuring device tomeasure the length of the supplied chain packing in order to easilydefine the supplied weight of reinforcing fibres 3 to the mixing silo.

[0029]FIG. 3 shows a chain packing 10, wherein packages or sacks 20contain reinforcing fibers 30 having lengths corresponding to the widthsof sacks 20. Sacks 20 are connected on one side thereof to a tape orstrip 40. The strip 40 can be replaced by a wire, a cord, and the like.The strip 40 is made of a material disintegrable in the concrete to bereinforced.

1. A method of dosing reinforcing fibers in a mixing silo during themanufacturing of fiber concrete, comprising: a) supplying concretereinforcing fibers in a chain packing of sacks, the sacks being made ofa material which can be disintegrated in one of mortar and concrete. 2.Method as in claim 1, wherein: a) the chain packing includes a stripconnecting the sacks.
 3. Method as in claim 2, wherein: a) the strip ismade of a material which can be disintegrated in one of mortar andconcrete.
 4. Method as in claim 1, wherein: a) the reinforcing fibersare arranged in the sacks in a substantially mutually parallel position.5. Method as in claim 1, wherein: a) a length of the respectivereinforcing fibers corresponds substantially to the respective lengthsof the sacks; and b) the reinforcing fibers are situated lengthwise inthe respective sacks.
 6. Method as in claim 1, wherein: a) a length ofthe respective reinforcing fibers corresponds substantially to therespective width of the sacks; and b) the reinforcing fibers aresituated widthwise in the respective sacks.
 7. Method as in claim 1,wherein: a) the sacks are joined in a line.
 8. A method for dosingreinforcing fibers in a mixing silo during manufacturing of fiberconcrete, comprising: a) supplying the fibers in a chain packing ofsacks; b) cutting open the sacks a sufficient amount and above themixing silo so that the reinforcing fibers fall out of the sacks intothe mixing silo; and c) conveying away the cut open chain packing. 9.Method as in claim 8, wherein: a) the sacks are joined to each other.10. Method as in claim 8, wherein: a) the reinforcing fibers arearranged in the sacks in a substantially mutually parallel position. 11.Method as in claim 8, wherein: a) a length of the respective reinforcingfibers corresponds substantially to the respective lengths of the sacks;and b) the reinforcing fibers are situated lengthwise in the respectivesacks.
 12. Method as in claim 8, wherein: a) a length of the respectivereinforcing fibers corresponds substantially to the respective width ofthe sacks; and b) the reinforcing fibers are situated widthwise in therespective sacks.
 13. Method as in claim 8, wherein: a) the sacks arejoined in a line.
 14. A chain packing for use in a method of dosingreinforcing fibers in a mixing silo during the manufacturing of fiberconcrete, the chain packing comprising: a) a plurality of sacks; and b)the plurality of sacks being filled with concrete reinforcing fibers.15. Chain packing as in claim 14, wherein: a) the plurality of sacks ismade of a material which can be disintegrated in one of mortar andconcrete.
 16. Chain packing as in claim 14, wherein: a) the sacks arejoined to each other.
 17. Chain packing as in claim 14, wherein: a) thereinforcing fibers are arranged in the sacks in a substantially mutuallyparallel position.
 18. Chain packing as in claim 14, wherein: a) thereinforcing fibers are made of steel.
 19. Chain as in claim 14, wherein:a) a length of the respective reinforcing fibers correspondssubstantially to the respective lengths of the sacks; and b) thereinforcing fibers are situated lengthwise in the respective sacks. 20.A method for dosing reinforcing fibers in a mixing silo duringmanufacture of fiber concrete, comprising: a) supplying the concretereinforcing fibers in a chain packing of sacks; b) cutting open thesacks a sufficient amount and above the mixing silo so that thereinforcing fibers fall out of the sacks into the mixing silo; and c)conveying away the cut open chain packing.
 21. Method as in claim 20,wherein: a) the sacks are joined in a line.